This invention relates generally to fluid handling equipment and more particularly to devices for shielding the spray from sprinklers used in irrigation.
For some time it has been relatively common to use sprinkler irrigation in agriculture as well as for household gardens. One popular form of these sprinkler systems uses standpipes or risers which rise vertically from a main supply pipe either permanently placed underground or novably located on the ground surface. Sprinklers are mounted in the top of these standpipes which deliver a spray of water to the surrounding area. Some of the sprinklers have a facility for effectively limiting their area of coverage to less than the entire circular area around them, others do not. Since such sprinklers are often located near roadways, driveways, walkways, buildings or other structures or areas in which it is not desirable to have water sprayed, devices for shielding or deflecting spray from a certain segment of the sprinklers' normal area of coverage have been developed.
The following United States patents have been located which illustrate generally the state of the prior art. These are all of the patents or publications pertinent to the prior art of which I am presently aware.
______________________________________ Date Issued Patentee U.S. Pat. No. ______________________________________ May 19, 1931 W. Van E. Thompson 1,806,100 Nov. 21, 1950 H. H. Owbridge 2,530,779 Oct. 13, 1942 A. Johnson 2,298,765 Nov. 28, 1972 James W. Schreiner 3,703,993 Nov. 21, 1961 R. McKay 3,009,652 ______________________________________
Of this prior art, the devices disclosed in patents to McKay and Thompson are best adapted to fill the need to which my invention is directed. That is, a shield which can be adjustably mounted on a sprinkler standpipe to provide a deflector which prevents spray from the sprinkler from entering a segment of the sprinklers' normal area of coverage. Each of these devices has substantial disadvantages which my invention overcomes.
Particularly in agricultural use, shields of this type must be fairly substantial in size and weight because the sprinklers are large and deliver a powerful spray. Also, in agricultural use the standpipes are larger in diameter and higher than for garden use. In addition, the supply pipes are usually laid above ground and moved from place to place as irrigation is desired. Therefore, the shields must be attached and detached from the standpipes to suit the particular circumstances in the area where the irrigation is being carried out. Although my invention will work well in garden sprinkler systems, it is most useful in the larger, more powerful, movable sprinkler systems used in agriculture.
The shield shown in the McKay patent is typical of those presently in use in agriculture. It is obviously designed for permanent installation on the standpipe, but even if the attachment clamps were "C" shaped so they could be removed from the standpipe without first removing the sprinkler, considerable effort is required to attach, detach and adjust the device. Worse of all, the adjustments and attachments are all made with set screws and around water these screws readily rust and become unworkable.
The device shown by McKay appears simple to attach but is not capable of forming a secure enough attachment to support the larger shields required for agricultural usage, for if the bottom clamp of Thompson's were made rugged enough to support a large, heavy shield it would be difficult, if not impossible, to release it from the standpipe by hand.
Accordingly, a need still exists for a sprinkler shield which can be made rugged enough for agricultural use and is still readily attachable and detachable by hand and without the use of any tools.